In addition to variable functions, there are call_user_func, call_user_func_array and even ReflectionMethod. Just be careful not to set the function name directly from user input, else you'll be opening your script to injection.
PHP Code:
$allowedThings = array_flip(array('aFunc', 'anotherFunc', 'yaf', ...));
function dostuff($stuff) {
foreach ($stuff as $thing => $args) {
if (is_array($args)) {
call_user_func_array($thing, $args);
} else {
call_user_func($thing, $args);
}
}
}
$stuffToDo = array_intersect($stuff, $_REQUEST[]);
dostuff($stuffToDo);